{"version":"2.1.312","anchor":"write-guard-message-for-partially-read-files","canonical_anchor":"write-guard-message-for-partially-read-files","heading":"Claude is warned before overwriting a file it has only partly read","tier":"notice","area":"File Tools","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.312\/e\/write-guard-message-for-partially-read-files","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.312","markdown":"### Claude is warned before overwriting a file it has only partly read\n\nIf Claude tries to overwrite a file it saw only the start of, a message tells it to edit the file or read all of it first\n\n**What**\n\nThe Write tool replaces a file's whole contents. Claude may have seen only the beginning of a file, with nothing showing that it later read the whole file in one go. If it then tries to use Write on that file, Claude Code shows it a message. The message tells Claude to do one of two things:\n\n- Use the edit tool to change only part of the file.\n\n- Read the whole file in one call first. If the file comes back in pages, try again with the option to read it in full.\n\n**Why**\n\nThis stops Claude from overwriting a large file and losing the parts it never saw.\n\n- Area: File Tools\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}